java - hibernate 如何将一个实体扩展到所有实体

Question

我有两个字段应该出现在每个表中。所以我想创建一个实体来保存这些字段，我的其他实体继承了这些字段 但是，当我运行查询时，出现错误 - org.hibernate.QueryException: could not resolve property: active of: com.db.tables.PersonTable 我做错了什么？

所有实体的基类都应该继承这些字段

@XmlRootElement
@Inheritance(strategy=InheritanceType.SINGLE_TABLE)
public class BaseTable implements Serializable
{
    private static final long serialVersionUID = 1L;

    @Column(name = "Updated")
    @JsonProperty
    @NotNull
    protected Timestamp updated;

    @Column(name = "Active")
    @JsonProperty
    @NotNull
    protected byte active;

    public BaseTable ()
    {
        active = (byte)1;
        updated = DbUtils.getCurrentTimeStamp();
    }


    public byte getActive()
    {
        return active;
    }


    public void setActive(byte active)
    {
        this.active = active;
    }


    public Timestamp getUpdated()
    {
        return updated;
    }

    public void setUpdated(Timestamp updated)
    {
        this.updated = updated;
    }

    @Override
    public String toString()
    {
        return new ReflectionToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE).toString();
    }


    @Override
    public int hashCode()
    {
        final int prime = 31;
        int result = 1;
        result = prime * result + active;
        result = prime * result + ((updated == null) ? 0 : updated.hashCode());
        return result;
    }


    @Override
    public boolean equals(Object obj)
    {
        if (this == obj) return true;
        if (obj == null) return false;
        if (getClass() != obj.getClass()) return false;
        BaseTable other = (BaseTable) obj;
        if (active != other.active) return false;
        if (updated == null)
        {
            if (other.updated != null) return false;
        }
        else if (!updated.equals(other.updated)) return false;
        return true;
    }


}

继承的类

@Entity(name = "Persons")
@Table(name = "Persons")
public class PersonTable extends BaseTable implements Serializable
{
    private static final long serialVersionUID = -5793514680136648542L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "PersonId")
    private short       personId;

    @OneToOne(cascade = CascadeType.ALL)
    @JoinColumn(name="personId")
    PortalUserTable portalUser;

//getters&settersand more fields 
}

多一个类继承

@Entity(name = "PortalUser")
@Table(name = "PortalUser")
public class PortalUserTable extends BaseTable implements Serializable
{
    private static final long serialVersionUID = -5793514680136648542L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "PersonId")
    private short       personId;

    @OneToOne
    (mappedBy = "portalUser")
    PersonTable person;

//getters&settersand more fields 
}

查询

public ObjectDaoResponse getAllTigrisUsers() throws JsonProcessingException  
{
    try
    {
        Query q = sessionFactory.getCurrentSession().createQuery("SELECT new com.db.queries.users.User( u.portalUserId ,p.personName) FROM PortalUsers u INNER JOIN u.person p WHERE portalUserId = p.personId AND p.active = 1 AND u.active = 1"); 
        List<TigrisUser> l = q.list();
        return ObjectDaoResponse.getAnOkResponse(l);
    }
    catch(Exception e)
    {
        System.out.println(e);
        return ObjectDaoResponse.getGeneralFailureResponse();
    }
}

Answer 1

@MappedSuperclass 公共(public)类 BaseTable ...

我建议更改命名约定 Base(Table) -> Base(Entity)。对所有实体类执行相同的操作。

您应该注意继承策略 - https://en.wikibooks.org/wiki/Java_Persistence/Inheritance